Simplify domain membership logic
Simplify domain membership logic

I think this was a holdover from multi-domain organizations.  It did
some weird permissions aggregations stuff that was getting in my way.

qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq